Seems that it's more efficient just to let 911 take all calls and route appropriately. Taking calls, determining if the situation is urgent, getting the necessary information from possibly panicked callers, etc. I know that a law enforcement officer told us to always call 911 if we saw illegal activity, because if nothing else they periodically map the calls and use that to determine where to patrol.

It shouldn't take more than a few seconds to determine most non-urgent calls aren't urgent and transfer them somewhere else.